The present invention relates to orthopedic implant positioners and impactors adapted to engage the convex or part-spherical outer surfaces of implants such as shoulder implants, acetabular implants and part-spherical heads for hip implants. The inserters/impactors may also be used on concave or part-spherical inner surfaces such as in acetabular cups.
Orthopedic implant positioners and impactors assist the surgeon in positioning and implanting prosthetic bearing surfaces particularly those bearing surfaces which include a threaded opening, which opening typically is a threaded central opening for accommodating a threaded post portion of the positioner/impactor. During the implantation, the surgeon will typically impact the instrument while the distal end of the positioner is in contact with the exterior or interior surface of the part-spherical implant.
U.S. Pat. No. 5,364,403 relates to an acetabular cup positioner having a resilient collar carried on the distal end of an insertion instrument which resilient collar prevents damage to the interior of an acetabular cup during impaction. The instrument has a threaded connector for engaging threads on a bore extending along the central axis of the acetabular cup. The connector is movable within the instrument and is biased towards the distal end of the instrument by a helical spring.